The invention relates to the field of orthodontic springs used for the movement of teeth in dentistry. The prior art teaches several alternate spring devices for separating, rotating and righting teeth which require orthodontic attention. Among the prior art springs is a double loop spring having a pair of legs which move toward each other within the plane of the tooth interface, thereby applying a separating force to the teeth by wedging itself between the teeth on opposite sides. In another form, the spring's legs are initially forcefully wedged between and thereby separate adjacent teeth. One example of the latter device has double legs which are forced into an overlap position upon installation thereby generating a lateral spreading force to adjacent teeth. This approach has the disadvantage of providing the largest force at the moment of installation but which thereafter rapidly diminishing.
Patents: U.S. Pat. Nos. 2,897,598, 3,052,029, 3,664,023, 3,827,082, and 4,256,456, fully describe the prior art. These prior springs are generally bulky, providing discomfort to the wearer as they are made of relatively heavy gauge wire and sheet materials which protrude beyond the tooth line thereby interfering with normal speaking and eating function. Some of these devices are designed to penetrate the gum ridge or are forcefully wedged between teeth thereby causing pain and in some cases, extreme discomfort. The orthodontics field is only now starting to realize that the prior art springs have spring rates several times larger than is required for successfully moving teeth in the practice. Also, prior art springs often have complex shapes requiring expensive tooling and added labor for fabrication. To summarize, the prior art teaches orthodontic springs which are bulky, have complex shapes, are uncomfortable and painful to wear, which are difficult to install and which often rotate or fall out of place after a short time. The material most often used in prior art springs is a stainless steel which has high stiffness and low elastic limit and therefore is often permanently deformed during insertion thereby reducing its effectiveness. This material cannot apply a uniform force over the range of tooth separation desired so that more frequent application is required.
Therefore, there exists a need for an inexpensive orthodontic spring for applying a relatively small but continuous force, over the range of desired separation of adjacent teeth to enable movement with little discomfort to the wearer. The present invention fulfills these needs in a relatively inexpensive fashion and provides further related advantages as described and shown herein.